1. Field of the Invention
This invention relates to a novel loudspeaker system having at least one ported sound directing and focusing tube attached to the back of a conventional speaker frame. In another embodiment at least one tube forms a speaker frame for supporting a speaker diaphragm.
2. Description of the Prior Art
In the prior inventions, attempts have been made to design an efficient loudspeaker system capable of accurately reproducing original high-fidelity sound. Specifically, attempts have been made in two areas of the loudspeaker system: improvement in the loudspeaker cone and diaphragm utilizing modern technology, i.e., improved materials, and improvement in the housing to reduce unwanted vibration and resonation within the housing. A loudspeaker system utilizing or manipulating sound waves directed toward the rear of the speaker has been proposed, for example, in U.S. Pat. Nos. 4,439,644 to Bruney, III, 4,524,846 to Whitby, and 4,807,293 to Weckler.
In U.S. Pat. No. 4,439,644 to Bruney, III (Bruney), a loudspeaker system utilizes a plurality of vinyl sheets having different thicknesses to seal the rear of a speaker housing, to relieve pressure behind the loudspeaker driver, and to attenuate sound waves emitted toward the rear of the speaker. While this type of system minimizes the housing vibration and generation of the spring-like compression effect or the resonant boosting effect often associated with an acoustic suspension enclosure, the speaker is not as efficient as a ported speaker system in general. By contrast, the present invention relates to porting the rear of a speaker system to amplify or concentrate sound waves which are emitted toward the rear of the speaker and to selectively direct the sound waves at any direction.
In U.S. Pat. Nos. 4,524,846 to Whitby and 4,807,293 to Weckler, a loudspeaker system directs sound waves radiated rearwardly into the chamber(s) in the housing through convoluted path. This type is known to provide a good reputable performance. However, due to sound waves colliding against baffles stationed in the housing, resonance in the baffle and the housing cannot be avoided when driving at high levels, thus minimizing the high fidelity capability. By contrast, the present invention provides sound collecting tubes which are directly attached to the speaker frame or which form the speaker frame. In the present invention there are no baffle or medium which can cause resonation or unwanted sound reflections within the speaker housing. Sound waves passing through the tubes are freely "breathable". In other words, pressure build-up behind the speaker and sound reflections within the confines of the speaker housing, which cause undesirable sound distortion, are avoided or at least minimized by routing sound waves through the tubes.